Immunology Flashcards
(388 cards)
1
Q
IL 2 is produced primarily by _____
A
Helper T cells
2
Q
What is the major growth factor for T lymphocytes (Interleukin ___)
A
IL2
3
Q
______ binding to t cell receptors stimulates the secretion of IL2 and the expression of IL2 receptors
A
Antigen
4
Q
IL2 promotes growth and differentiation of T and B cells as well as activates ____ and _____ .
A
Natural killer cells
Monocytes
5
Q
What are IL2 anticancer effects as treatment for metastaticmelanoma and renal cell carcinoma
A
IL2 increases natural killer cell and T cell activity
6
Q
Why is the H. Flu vaccine administered as a capsular polysaccharide from H. Flu conjugated to a tenanous toxoid
A
Polysacharides only elicit B cell responses which do not elicit memory resulting in short relative duration of immunity
Polysaccharide-protein conjugate vaccine ellicits a B and T cell response –> memory -> longer immunity
7
Q
Why are polysacharide vaccintions not effective in children <2?
A
They have immature humoral immunity (polysaccharide capsule rovokes an antibody-mediated immune response)
8
Q
T-cell dependent antigen stimulates which two effects that increase the efficacy of protein conjugated vaccine compared to polysaccharide capsule vaccines?
A
T cell dependent stimulation of B lymphotcytes
Production of memory B lymphocutes
9
Q
Type I (alpha and beta) interferons are synthesized by most human cells in response to _____
A
Viral infections
10
Q
Secrete alpha and beta type one interferons bind receptors on __________
A
Neighboring cells (paracrine and autocrine signaling)
11
Q
Binding of alpha and beta interferons to interferon I receptors leads to the transcription of what enzymes?
A
Antiviral enzymes (halt protein synthesis): RNase and protein kinase R
12
Q
Antiviral enzymes transcribed by alpha and beta interferon activity during viral infections become active only in the presence of ______
A
Double stranded RNA
13
Q
Effect of alpha and beta interferons during viral infection:
A
Supress viral replication by haltingprotein synthesis
Promote apoptosis of infected cells
14
Q
Each molecule of MHC class I protein consists of __________ and an associated beta 2- microglobulin
A
Single heavy chain
15
Q
Each molecule of MHC class I consists of a single heavy chain and an associated _____________
A
Beta 2 microglobulin
16
Q
Heavy chains are highly _______ which allows them to present a large variety of antigens
A
Polymorphic
17
Q
Viral polypeptides are processed in the host cell and combined with MHC class I in the __________
A
Endoplasmic reticulum
18
Q
Structural features of MHC class II include ____ and ______ polypeptide chains
A
Alpha and beta
19
Q
MHC class ______ has alpha and beta polypeptide chains
A
II
20
Q
MHC class I is found on the surface of what cell type
A
All nucleated cells
21
Q
MHC class II is found on what cell type
A
Antigen presenting cells (B cells, macrophages, dendritic cells, langerhans cells
22
Q
What type of antigens are presented by MHC class I
A
Virus and tumor proteins
23
Q
Where are antigens that are presened on MHC class I molecules processed
A
Cytoplasm
24
Q
What antigens are presented on MHC class II molecules
A
Bacteria
25
Where are antiges presented on MHC class II molecules processed
They are phagocyosed and digested by lysosomes within which antigen binds to MHC II
26
Antigen presentation by an MHC class I molecule results in
Apoptosis of hte presenting cell
27
MHC class I present endogenous antigens to ___ cells
Cytotoxic T cells (CD8)
28
How do reactive T lymphocytes appear differetly than normal T lymphocytes
reactive are larger
Abundunt cytoplasm
Scalloped edge
29
Reactive lymphocytes are activated, pathogen-specific _____ and ______that form in response to certain intracellular infections
Cytotoxic T cells
| Natural killer cells
30
Reactive lymphocytes are associated to certain intracelullar infections such as HIV, CMV, and toxoplasmosis but are particularly linked to
```
Infectious mononucleosis (primary Epstein-Barr virus)
(Reactive lymphocytosis is a diagnostic feature of infectious mononucleosis)
```
31
Reactive lymphocytes are effector cells that contain cytotoxic granules composed of ____ and _____
Perforin
| Granzymes
32
Function of perforin
Creates holes in the infected cell's membrane
33
Granzyme function
Enter the cytoplasm of infected cells and trigger cell death
34
History of recurren respiratory infections and dextrocardia suggest what diagnosis
Kartagener syndrome (primary ciliary dyskinesia (PCD))
35
Mode of inheritence for kartagener syndrome
Autosomal recessive
36
Eukaryotic flagella and ciliar are composed of central core known as the _______
Axoneme
37
The axoneme of flagella an motile cilia consists of a circular array of microtubule doublets surrounding 2 central microtubules called what kind of arrangement
9 + 2 arrangement
38
The axoneme of flagella and motile cilia is anchored to the cell by a _______
Basal body
39
Each microtubule doublet in cilia and flagella have A and B subunits that are connected to adjacent doublets via
Dynein arms
40
What is the function of dyenin arms?
Contain ATPase that generates energy to slide microtubules past each other --> ciliary movement
41
Failure of dyenin arm to develop normally can result in ______
Primary ciliary dyskinesia
42
Ankylosing spondylitis has increased production of what cytokines
Il-17
TNF alpha
Prostaglandins
43
Ankylosis sonylitis has increased risk with what HLA?
HLA-B27
44
Pain presentation of ankylosing spondylitis
Back and buttock pain that is relieved with exercise and worse at night
45
Clinical findings in ankylosing spondlitis
Redced chest expainsino, enthesitis (tenderness at tendon insertion sites), dactylitis (swelling of fingers and toes), anterior uveitis
46
What is "bridging syndesmophytes"? (A finding in ankylosing spondylitis)
Ossification at vertebral body margins ("bamboo spine")
47
Where is ankylosing spondylitis thought to originate from? (Whats the cause)
The gut: defects in mucosal barrier and an abnormal intestinal microbiome --> inflammation
48
IL-17 mediates an inflammtory response via which cell type
Innate lymphoid cells and helper T cells (Th1, Th17)
49
IL-17 stimmulates production of which additional inflammatory factors
TNF alpha and prostaglandins
50
What is the effect of high IL-17, TNF-alpha, and prostaglandings in the joints of someone with ankylosing spondylitis?
Bony erosions and abnormal bone growth
| Bone erosion --> subchondral sclerosis --> ankylosis (bony fusion
51
Treatment for ankylosing spondylitis
NSAIDS (inhibit prostaglandin formation)
Anti-TNF alpha agents (etanercept, infliximab)
Anti-IL-17 agents (secukinumab)
52
Neoantigens are displayed on MHC class ____ molecules and subsequently recognized by _____ cells
I
| Cyotoxic T cells
53
Over expression of programmed death ligand 1 (PD-L1) on cancer cels surface binds PD-1 receptor on T cells to what result
Supresses T cells ability to induce apoptosis: "T cell exhaustion"
54
Pembrolizumab mechanism of action
Monoclonal antibody that blocks PD-1 (restores cytotoxic t cell response (disinhibition) in cancers that overepress PD-L1)
55
Cells and humoral components involved in type I hypersenstivity reactions:
IgE
Basophils
Mast cells
56
Humoral components and cellular components involved in type II hypersensitivity reactions
```
IgG and IgM autoantibodies
Complement
NK cells
Eosinophils
Neutrophils
Macrophages
```
57
Goodpasture and autoimmune hemolytic anemia are examples of what type of hypersensitivity reaction?
Type II (cytotoxic)
58
What humoral and cellular components are involved in type III hypersenesitivity responses
Deposition of antibody-antigen complexes
Complement
Neutrophils
59
Serum sickness, PSGN, and lupus nephritis are examples of what type of hypersensitivity reaction
Type III (immune complex)
60
anaphylaxis and allergies are examples of what type of hypersensitivty reaction
Type I (immediate)
61
Type 4 hypersensitivity reactions include what humoral and cellular components
T Cells
Macrophages
(No humoral components)
62
Contact dermatitis and tuberculin skin test are examples of what type of hypersensitivity reaction
Type 4 (delayed type)
63
What changes occur on initial exposure to an allergen in a patient who will eventually develop an allergic response
Antibody class switching to IgE which bind IgE receptors on basophils (blood) and mast cells (tissues)
64
What changes does a second exposure to an allergen illicit
Allergen interacts with cell bound-specific IgE which crosslik and cause degranulation of mast cells
65
Major antibody for mucosal immunity:
IgA
66
Plasma cells synthesize IgA linked by ______
J chain
67
IgA dimers bind to ________ on basolateral surface of intestinal epihelial cells and undergo transcytosis.
Polymeric immunoglobulin receptor (pIgR)
68
As the linked IgA dimer is released into the intestinal lumen, a portion of pIgR remains attached to the antibody (called _______ )
Secretory component
69
Live attenuated vaccines generally produce a ________ immune response than killed vacines by acting as a persistent stimulus that better activates helper and cytotoxic T cells
Stronger
70
Live attenuated oral vaccine will have a significantly higher IgA response in the __________ than a inactivated injected vaccine
Oropharyngeal and intestinal mucosa
71
Increase in mucosal IgA offers immune protection where
At site of viral entry by inhibiting attachment to intestinal epithelial cells
72
Name for the live attenuated oral poliovirus vaccine
Sabin
73
Name for the inactivated poliovirus vaccine
Salk
74
In _______________ donor T cells from the graft migrate into host tissues where they recognize host MHC antigens and become sensitized ---> CD4 and CD8 donor cell activation ---> destruction
Graft versus host disease (GVHD)
75
Graft versus host disease is a condition that usually occurs after allogeneic bone marrow transplantation but can occur following transplantation of organs rich in ________
Lymphocytes (or transfusion of non irradiated blood)
76
Patients affected by GVDH are generally severely ______ which allows donor T cells to survive
Immunodeficient (due to primary disease process or result of immunosuppressive therapy)
77
What organs are most commonly affected by graft versus host disease
```
Skin (maculopapular rash, especially palms and soles of feet)
GI tract (diarrhea, intestinal bleeding, abdominal pain)
Liver (abnormal liver function tests)
```
78
Sialyl lewis X or PSGL-1 bind what on neutrophils to induce rolling in leukocyte accumulation
L-selectin
79
Selectins are involved in which phase of leukocyte accumulation
Rolling
80
Integrins (activated by chmokines) change to high affinity state in which phase of leukocytosis adhesion cascade
Activation
81
Neutrophils bcome firmlia attached to the endothelium via binding of ________ to ________ on endothelial cells
CD 18 beta 2 integrins (MAC-1 and LFA-1)
| Intercellular adhesion molecule 1 (ICAM-1)
82
Transmigration of the nutrophils is accomplished by squeezing between the cells via integrin attachments and adherence to ______________
Platelet endothelial cell ahesion molecule 1 (PECAM-1)
83
In ____________ disease leukocytes cannot leave the vasculature to migrate into tissue under conditions of inflamation
Leukocyte adhesion deficiency (LAD)
84
LAD type 1 is the absence of _______
CD18
85
In LAD type 1, there is an absence of CD18 which leads ot inability to synthesize _________ , affecting tight adhesion, crawling, and transmigration
Beta 2 integrins: MAC-1 and LFA1
86
Clinical manisfestation of LAD type 1
Recurrent skin infections without pus formation
Delayed detachment of umbilical cord
Poor wound healing
87
LAD type 2 is due to impaired fucosylation of sialyated carbohydrates ligands which prevents binding to ______
Selectin
88
LAD 3 is due to impaired cytokine signaling which prevents ______ activation
Integrin
89
What in the HBV vaccine generates protective immunity against the virus?
Recombinant HBsAg
90
How are people with the HBV vaccine immune?
Patient will generate anti-HBs antibodies which bind circulating viral partcles and prevents attachment ot and penetration of hepatocytes
91
During sensitization to an allergen, the antigen is presented on MHC II which activates what cell type
Helper T cells
92
During sensitization to an allergen, helper T cells are activated by allergen antigen on MHC II and epithelium release of ______ and _______ to become a Th2 cell
IL-25 and IL-33
93
Th2 cells secrete what cytokines to induce B cell classs switching to IgE produciton
IL-4, IL-13
94
Which immune cells are responsible for the destruction of cells with decreased or absent MHC class I proteins on their surface
NK cells
95
Cells markers on NK cells
CD16 or CD56
| Do NOT express CD 4, 8, or3
96
Do NK cells require the thymus for maturation?
No (present in athymic patients)
97
Do NK cels have antigen specific activities/require antigen for activation?
No
98
What cytokines activate NK cells
Interferon gamma and IL-12
99
Duing a parasitic infection, Th 2 induces eosinophil prolferation via release of what cytokine
IL-5
100
How are hemilinths destroyed by the immmune system?
Antibody dependent cell mediated cytotoxiity
IgG and igA antibodies coating the helminth bind the Fc receptors on eosinophil cell surface --> degranulation and release of cytotoxic proteins and reactive oxygen intermediates o destroy the paraste
101
What cyctotoxic protein is released from eosinophils
Major basic protein
102
What cell contributes to the late phase of a type 1 hypersensitivity reaction
Eosinophils (release prostaglandins, leukotrienes, and cytokines)
103
How does macrophage response to TB infection change over a few weeks once infected?
Initially the pathogen escapes phaolysosome s in alveoar macrophages
After a few weeks APCs start to display mycrobacterial antigens on MHC II and release IL-12 --> Th1 differentiation --> interferon gamma secretion --> macrophage activation --> fully maturephagolysosomes destroy intracellular bacteria and differentiat e into epitheliooid and langhans giant cells to surround extracellular bacteria forming a granuloma
104
What is released from APCs to differentiate naive CD4 cells into Th 1 cells
IL-12
105
What is released from Th1 cells to activate macrophages
Interferon gamma
106
How do granulomas limit myobacteria proliferation
Their acidic and hypoxic central environment limits proliferation (but usually does not eliminate the infection)
107
Tuberculin skin test is what type of hypersensitivity reacion
Delayed type/T-cell mediated
108
Why may some people have a negative tuberculin skin test if they were recently exposed to TB but a positive test a few weeks later
The cell mediated response takes several weeks to form
109
What is a Ranke complex
Calcified lower lobe nodule and ipsilateral hilar lymph node
Often seen in TB patients even when asymptomatic
Takes several months to form
110
What tranfusion reactions occur minutes to hours after transfusion
Allergic and acute hemolytic
111
What causes an allergic transfusion reaction
Preformed antibodies against blood product component
112
What causes an acute hemolytic transfusion reaction
ABO incompatibility (often clerical error)
113
How does an allergic transfusion reaction present
Anaphylaxis and urticaria within minutes-hours of transfusion
114
How does acute hemolytc transfusion reaction present
Fever, flank pain, hemoglobinuria, DIC, positive Coombs test minutes - hours after transfusion
115
How does a febrile nonhemolytic transfusion reaction present
Fever and chills hours after transfusion
116
What causes a febrile non hemolytic transfusion reaction
Cytokine accumulation during blood storage
117
How does a transfusion-related acut lung injury present following a blood transfusion
Respiratory distress and bilateral pulmonary edema hours after trnsfusion
118
How does delayed hemolytic transfusion reaction present
Often asymptomatic, labratory evidence of hemolytic anemia, and + Coombs test days-weeks following blood transfusion
119
What is the cause of transfusion related acute lung injury
Donor antileukocyte antibodies
120
What is the cause of delayed hemolytic transfusion reaction
Anamnestic antibody response
121
What is required for a patient to have an anamnestic response (delayed hemolytic transfusion reaction) to a blood transfusion
A previous exposure to a foreign minor red blood cell antigen (non-ABO) such as pregnancy, prior blood transfusion, or intravenous drug use
122
Activation of Fas receptor leads to what?
Extrinsic pathway of apoptosis
123
Upon binding Fas ligand, Fas receptors trimerize to allow their death domains to form a binding site for ______
Fas-associated death domain
124
Receptor bound Fas associated death domain (FADD) stimulated activation of __________
Initiator capsoses 8 and 10
125
Initiation caspases 8 and 10 begin an activaion cascade culminating in the activation of _________
Executioner caspases 3 and 6
126
Executioner caspases 3 and 6 initiate terminal processesof apoptosis such as:
Cleavage of DNA
Fragmentation of the nucleus
Organelle autodigestion
Plasma membrane blebbing
127
What cells express Fas receptors
T lymphocytes
128
Activation-induced cell death is apoptosis of T lymphocytes due to constant presence of what stimulating self-antigens
Fas L
129
Mutations involving Fas or FasL result in excessive accumulation of ____________ and development of autoimmune diseases such as systemic lupus erythematosus
Autoreactive T-cells
130
Is parapneumonic effusion fluid in the pleural space exudative or transudative
Exudative
131
Why do infections and inflammtory tissue injuries cause pleural effusion
They increase vascular permeability (allows protein rich exudates to cross)
132
What is the most potent chemotactic eicosanoid
Leukotriene B4
133
Which leukotrienes cause bronchospasms and increas bronchial mucus secretion, playing a large role in asthma pathogenesis
LTC4, LTD4, LTE4
134
5-HETE (leukotriene precursur), C5a, and IL-8 are all important __________ agents
Chemotactic
135
What type of necrosis is seen in TB
Granulomas with caseating necrosis
136
In TB, granuloma with caseating necrosis consist of what cells
Large epithelioid macrophages
137
The most specific cell surface marker of the monocyte-macrophage cell is _______, which binds to bacterial lipopolysaccharide
CD14
138
The most specific cell surface marker of the monocyte-macrophage cell lineage is CD14, which binds to bacterial _________
Lipopolysaccharide
139
The caseating granulomas of tuberculosis are almost alway surrounded by large epitheliod macrophages with __________ cytoplasm
Pale pink granular
140
Classic features of melanoma: (5)
```
Asymmetry
Border irregularity
Color varegation
Diameter > 6 mm
Evolution over time
(A, B, C, D, E)
```
141
What is color variegation (common feature of melanoma)
Different colors representing different areas of activity within the tumor
142
In color variegation in melanoma, what do red areas indicate
Vessel ectasia (dilation) and local inflamaiton
143
In color variegation in melanoma, what do brown or black areas indicate
Flared areas along the border due to advancing, neoplastic melanocytes
144
In color variegation in melanoma, what do white and gray areas indicate
Cytotoxic lymphocytes recognize tumor antigens (melan-A) and induce apoptosis --> malignant melanocyte regression
145
Pembrolizumab mechanism of action
Programmed cell death receptor 1 inhibitor (PD-1 inhibitor)
146
Tryptase is an enzyme that is relatively specific to _____ cells
Mast
147
Elevated serum levels of tryptase are oten used to support clinical diagnosis of__________
Anaphylaxis
148
What is the receptor found on mast cells and basophils that normally binds the Fc portion of circulating IgE, coating the cell with various antigen specific IgE molecules
High affinity IgE receptor (Fc epsillon RI)
149
Crosslinking of multiple membrane bound IgE antibodies by a multivalent antigen results in ____________, causing degranulation and the release of preformed mediators that initiate an allergic response
Aggregation of the high-affinity IgE receptor
150
IgE class switching is initiated by ____ and _____ which is released by the Th2 cells
IL-4, IL-13
151
IgE class switching is initiated by IL-4 and IL-13 which are released from which cells
Th2
152
Cell mediated adaptive immunity (targetting intracellular pathogens) and type IV (delayed type) hypersensitivity reactions mainly involve Th___ cells
Th1
153
Excess of what cell type my underli the pathogenesis of asthma
Th2 (relative to Th1)
154
Th2 secretes IL- 5 which activates _____
Eosinophils
155
Th2 cells release ____ which activates eosinophils
IL-5
156
___ cells release IL-5 which activates eosinophils
Th2
157
_______ is a condition with a mutation in the bruton tyrosine kinase gene which casuses failure of bone marrow pre-B cells to develop into mature B cells
X-linked agammaglobulinemia (XLA)
158
X-linked agammaglobulinemia is a mutation in ________
Bruton tyrosine kinsae gene
159
Patients with X-linked agammagobulinemia have low or absent ____ in blood and lymphoid tissues and what other serum findin
B cells
| Pan-hypogammaglobulinemia (very low IgG, IgM, and IgA)
160
Patients with x-linked agammaglobulinemia have increased risk for infections with ______ bacteria, and viral and parasitic infections such as enteroviruses and Giardia lamblia de to absence of opsonizing nd neutrolizing antibodies
Pyogenic (encapsulated)
161
B cell surface protein cell markers
CD19
CD20
CD21
162
B lymphocytes aggregate in the cortex of lymph nodes to form lymphoid ______
Follicles
163
In the lymph node: ______ follicles are dense and dormant.
Primary
164
Secondary follicles have a plae __________ containing proliferating B cells in response to antigenic stimulus
Germinal center
165
Secondary follicles have a plae germinal center containing proliferating ______ cells in response to an antigeenic stimulus
B
166
Maternally derived antibodies wane how long after birth?
3-6 months
167
Superantigens interact with __________ on antigen presenting cells (macrophages) and with the _____ region of TCR
MHC
| Variable
168
Superantigens interact with MHC molecules on _____ and variable region on _____ receptors
Antigen presenting cells (ie macrophages)
| T-cell
169
Widespread activation of T lymphocytes by superantigens is responsible for release of _____ from T cells and _____ and ____ from macrophages which causes capillary lek, circulatory collape, hypotension, shock, fever, skin findings, and multi organ failure
IL-2
| IL-1 and tumor necrosis factor
170
A few weeks after infection with TB, ____ cells release interferon gamma which activated macrophages
Helper T cells
171
What is required, and happen a few weeks after a TB infection, inorder for helper T cells to release interferon gamma and activate amcrophages
Infected macrophages in draining lymph system display mycobacterial antigens on MCH II
172
CD4 cells release ____ that activates macrophages and increases their ability to kill phagocytosed organisms
Interferon gamma
173
Activated macrophagescan differentiate into _____ and coalesce into multinucleated langhas giant cells that wall of mycobacteria withing granuloma
Epithelioid histocytes
174
Activated macrophages can differentiate into epithelioid histpcytes and coalesce into __________ that wall off myobacteria within granulomas
Multinucleated langhans giant cells
175
The center of caseating granulomas is ____ and ____ which causes it to appear acellular, necrotic, and "cheese like" (caseating)
Acidic
| Hypoxic
176
Horse-shoe shaped, fused, activated macrophages = _______
Multinucleated Langhans giant cells
177
What type of burn has erythema that blanches without blistering
Superficial burn (1st degree)
178
Superficial (1st degree) burns damage only the ______
Epidermis
179
Superficial partial-thickness burns (2nd degree) damage the __________
Epidermis and upper dermis
180
Deep partial-thickness burns (2nd degree) damage the
Epidermis and most of the dermis
181
Full-thickness burns (3rd and 4th degree) damage ________
```
Entire dermis
(And may extend into fat, muscle, and/or bone)
```
182
Release of _____ from _____ cells results in blanching erythema that extends to the area surounding the initial burn
Histamine
| Mast cells
183
Damage to venules can resultin fluid extravasation through gaps between injured _________ cells --> blister
Venule endothelial cells
184
A blister is formed from a collection of serous fluid between the ___ and ____-
Dermis and epidermis
185
What is the earliest morphologic change that occurs after a superficial thermal burn
Erythema due to release of preformed mediators (histamine) from mast cells
186
Clostridium tetani poduces an exotoxin (tetanospasmin/ tetanus toxin). It travels by retrograde axonal transport through LMN and acts on the anterior horn cells to block _______
Inhibitory neurotransmission
187
Opisthotonos
Limb spasms
Hyperextension of back and neck
Due to blocked inhibitory neurtransmission from tetanus
188
What type of vaccine is tetanus vaccine
Tetanus toxoid vaccine (formaldehyde-inactivated tetanus toxin)
189
The tetanus toxoid vaccine (a formaldehyde inactivated tetanus toxin) stimulates ______ response against tetanus toxoid
Humoral antibody response
190
The tetanus immunization with an inactivated toxoid triggers production of antitoxin antibodies: _____ immunity
Active
191
Most common systemic vaculitis in children that presents with palpable purpura over buttocks and thighs
Henoch-Schonlein purpura (HSP)
192
Henoch-schonlein purpura (HSP) is caused by circulating _______
IgA-antigen immune complexes
193
What type of hypersensitivity reaction is henoc-schonlein purpura (HSP)
Type III (immune complex)
194
How does Henoch-schonleini purpura (HSP) cause hematuria
Deposition of immune complexes in renl mesangium
195
Wheal and flare lesions usually result from what type of hypersensitivity reactions
Type I
196
Sarcoidosis will have what finding on lung biospy
Non caseating granulomas
197
Non caseating granulomas are characterized by a central collection of tightly clustered _________ with abundant pink cytoplasm surrounded by a rm of mononuclear cells
Epithelioid macrophages
198
Sarcoidosis is thought to result from a dysregulated _____ immune respponse to an unidentified antigen which causes the formation of granulomas
Cell mediated
199
Cell mediated immunity is stimulated by _____ from antigen presenting cells which stimulate CD4 cells to differentiate into ____ cells
IL-12
| Th1
200
Th1 cells release ___ which stimulates the autocrine proliferation of Th1 cells
IL-2
201
Th1 cells secrete _______ which activated macrophages and promotes granuloma formation
Interferon gamma
202
Activated macrophages and T cells produce _______ which assists in leukocyte recruitment and granuloma maintenance
Tumor necrosis factor
203
Antigen presenting cells present extracellular antigens on MHC class ___
II
204
After phagocytosis or endocytosis, proteins are degraded in acidified _____
Lysosomes
205
Phagocytosed or endocytosed proteins are degraded in lysosomes and loaded onto MHC class ___
II
206
Proteasomes degrade proteins then the peptide fragments are sent to ______ where they are attached to MHC class I
ER
207
Acute rejection most often occurs within weeks or up to 6 months after transplant and is predominantly cell- mediated, involving sensitization of __________ against ________
Host T lymphocytes
| Donor MHC antigens
208
What cells are distinguished by presence of abundant basophilic cytoplasm, perinuclear paleness (large Golgi apparatus), and nucelei with "clock face" (peripheral) chromatin)
Plasma cells
209
Presence of >10% plasma cells in the bone marrow raises strong suspicion for ____________
Multiple myeloma
210
In multiple myeloma, neoplastic _____ cells crowd the bone marrow leading to impaired hematopoiesis
Plasma
211
People with multiple myeloma have limitted generation of targeted immunoglobins but have high levels of circulating ________ which does not provide immunity against diverse range of pathogens
Monoclonal immunoglobulin
212
Multiple myeloma is associated with renal insufficiency due to clogging of tubules with _________
Immunoglobulin light chains
213
HBsAg persisting over 6 months indicates ____
Chronic hepetitis B infection
214
A patient wih a traumatic ocular injury later developed a granulomatous inflammation of the contralateral eye. What condition is this
Sympathetic ophthalmia
215
Sympathetic opthalmia occurs when the contralateral eye of a traumatic ocular injury develops granulomatous inflammation due to robust ____ response to previously sequestered antigens in the eye
T cell
216
In order to limit potential organ damage that may result from robust inflammatory response, inflammaiton is inhibited by multiple mechanisms in certain anatomic sites. What is this called
Immune privilege
217
What may be released following traumatic eye injury (inherent immune privilege zone) causing immune response
Previously sequestered antigens that T cells recognize as foreign
218
The _______ of the Fc portion of the heavy immunoglobulin chains represents the site that binds to the Fc receptors on neutrophils and macrophages
Carboxy terminal
219
The carboxy terminal of the Fc portion of the _____ immunoglobulin chains represents the site that binds the Fc receptors on the neutrophils an macrophages
Heavy
220
Early phase of type I hypersensitivity reaction happens minutes after an exposure and presents as ____
Dermal edema and erythema(wheal and flare reaction) due to vasodition and increased capillary permeability
221
Late pase of type 1 hypersensitivity reaction presents as _____ , 2-10 hours after the early phase reaction
Indurated lesion
222
The late phase of a type I hypersensitivity reaction is caused by type 2 helper T cells releasing cytokines that activate eosinophils which release ______, causing tissue damage
Catioinic proteins (major basic protein, eosinophil peroxidase)
223
Following traumatic eye injury, granulomatous inflamation of both the injured and noninjured eyes is a condition known as ______
Sympathetic opthalmia
224
Sympatheticopthlmia occurs when there is a robust _______ response to previously sequestere antigens in the eye, an area that displays immune privilege
T - cell
225
Bradykinin is a potent vasodilator that ultimately increases vascular permeability and can cause what potentially fatal adverse effect?
Angioedema
226
What can present as tongue, lips, or eyelid swelling and less frequently, laryngeal edema and difficulty breathing and can be exacerbated by ACE inhibitors
Angioedema
227
_________ is a condition resulting from decreased expression of complement inactivating proteins on the surface of red blood cells--> increased formation of MAC ---> anemia due to complement-mediate hemolysis
Paroxysmal nocturnal hemogobinuria
228
Treatment for paroxysmal nocturnal hemoglobinuria
Monoclonal antbody (exulizumab) to a terminal complement component (ie. C5) which inhibits formation of MAC
229
Inhibition of MAC formation from eculizumab monoclonal antibody treatment for example results in loss of rapidcomplement -mediated killing of gram negative bacteria making patients espcially at risk to ______ infection
Neisseri meningitidis
230
Mechanism of action for etanercept in RA treatment
Tumor necrosis factor alpha inhibitor: fusion protein that links TNF alpha receptor to Fc component of hummon immunogloblin G1 (acts as decoy receptor)
231
Suffix "mad" meaning
Monoclonal antibody
232
Suffix "cept" meaning
Receptor molecule
233
suffix "nib" meaning
Kinase inhibitor
234
Wound healing requires formation of grunaltion tissue which is impaired by inflammation, therefore, release of ant-inflammatory cytokines such as ______ from macrophages and regulatory T cells supresses inflamation response and facilitates fibroblast proliferation and reepithelialization of the wound
IL-10
235
In patients with diabetes mellitus, constitutively elevatd blood glucose increases inflammation by stimulating the release of proinflammatory cytokines and _______ from neutrophiles
Reactive oxygen species
236
Elevated glucose leads to marked decrease in ____ production which contributes to an incerased susceptibility for chronic non healing wounds and ulcers
IL-10
237
In systemic lupus erythematosus, hematologic abnormalities are due to what type of hypersenitivity reaction while lupus nephritis is due to type ____ hypersensitivity reaction
Type I: autoantibodies against blood cell antigens --> pacytopenia
Type III: imune complex deposition --> lupus nephritis
238
A ________ uses specific antibodies and a fixed quantity of radiolabeled antigen to determine the amount of antigen present in an unknown sample
Radioimmunoassay
239
What is the function of TH1 cells
Activate macrophages and CD8 T cells
240
What immunity are Th1 cells involved in
Cell mediated
241
What cytokines are released from Th1 cells
IL-2. IFN-gamma, and lymphotoin beta
242
What immunity are Th2 cells involved in
Humoral
243
What are the roles of Th2 cells
Activate B cells and promote class switching
244
Cytokines released from TH2 cells
IL-4, 5, 10, and 13
245
Th1 cell diferentiaion is stimulated by a macrophage presenting an antigen and secreting ______
IL-12
246
Patients with IL-12 receptor deficiency are sysceptible to severe mycobacterial infections due to inability to mount a strong cell-mediated granulomatous immune response, therefore they require treatment with _____
IFN-gamma
247
Acute hemolytic transfusion reactions are examples of what type of hypersensitivity reaction
Type II (antibody-mediated)
248
The polysaccharide vaccine for strep pneumoniae covers how many serotypes
23
249
The conjugate vaccine for strep pneumoniae covers how many serotypes
13
250
Why is the 13 valend pneumococcal vaccine given to children instead of the 23 valent vaccine
The23 valent is polysaccharide vaccine and children under 2 have immature humoral anitbody response , also the antibody levels decline over 5 years in the 23 valent (bc no memory cells)
The 13 valent is a conjugate vaccine and allows for the development of memory B cells
251
What is the term for age-related immune decline
Immunosenescence
252
Why does immunosenscence occur
Loss of etlomere length during aging --> decreased produciton of rapidly providing cells such as naive B and T lymphocytes
253
Wht patients are at risk for a life threating infection of enterovirus
Infants with primary humoral immunodeficiency (ie x linked agammaglobulinemia) (enterovirus usually self limited)
254
Most activated B cells migrate to _______located in the lymph node cortex where they form germinal centers that are the site of B cell proliferation during the immune response
Lymphoid follicles
255
What is the main serum immunoglobulin of the secondary response to an antigen
IgG
256
Why do approximately 25% of patients with active TB have false negative TST test
Impaired lymphocyte response, immunocompromise (ie HIV), improper injection , or recent infection (it takes 8 wks ofo infection for cell mediated response to form)
257
Activation of complement by IgM prior to antigen binding is prevented how?
The C1 binding site is hidden while unbound IgM is circulating in its planar form
258
Adalimumab is a recombinant human IgG that binds ______ to prevent it from associating with cell surface receptors, thus blockng its pro-inflammatory effects, making it useful in treating Crohns, psoriasis, and rheumatoid arthritis
TNF alpa
259
Use of adalimumab can induce formation of _____ which reduces activity and increases drug clearance. Patients will show declining effectiveness of the treament
Antidrug antibodies (ADAs)
260
A positive C-ANCA vasculitis that primarily attaacks the upper/lower respiratory tracts, kidneys, and skin is what ?
Granulomatosis with polyangitis
261
Rituximab mechanism of action
Deplete B cell populations by binding CD20 --> Fc receptor mediated B cell cytotoxicity
262
hereditary angioedema is characterized by a deficiency or dysfunction of_______
C1 inhibitor
263
poor C1 inhibitor function leads to elevated _______
bradykinin
264
elevated brakykinin leads to what physical exam finding
edema (increases vasodilation and vascular permeability)
265
Complement level testing in hereditary angioedema will show ____
low C4
266
in the absence of C1 inhibitor, unregulated C1 activation leads to ____
unchecked cleavage of C4
267
3 characteristic findings of wiskott-aldrich syndrome
eczema
recurrent infections
thrombocytopenia
268
3 characteristic features of ataxia-telangiectasia
ataxia
telangiectasia
sinopulmonary infections
269
3 characteristic features of chediak higashi syndrome
oculocutaneous albinism
pyrogening infections
progressive neurologic dysfunction
270
2 characteristic features of chronic granulomatous disease
severe bacterial and fungal infections
| granuloma formation
271
3 characteristic features of DiGeorge syndrome
congenital heart disease
dysmorphic facies
hypocalcemia
272
3 characteristiv features of severe comnined immunodeficiency
severe bacterial and viral infections in infancy
chronic diarrhea
mucoccutaneous candidiasis
273
name a characteristic feature of terminal complement deficiency
recurrent neisseria infections
274
name 3 characteristic features of wiskott aldrich syndrome
reccurent infections that worsen with age
easy bleeding
ecxema
275
mode of inheritence of wiskott aldrich syndrome
X linked recessive
276
wiskott aldrich syndrome is caused by a mutation in cytoskeleton proteins that are critical for normal cell structure and cell to cell interactions required for activation of _______
hematologic cells
277
in patients with wiskott aldrich syndrome _____ are abnormally shaped and deficient leading to petechiae, purpura, hematemesis, and epistaxis
platelets
278
a deficiency of B cells such a in wiskott aldrich syndrome results in recurrent pyogenic infections due to inability to mount a humoral immune response against organisms with ______
```
polysaccharide capsule
(neisseria meningitidis, haemophilus influenzae, strep pneumo)
```
279
what is the treatment for wiskot aldrich syndrome
transplantation with HLA matched bone marrow
280
severe combined immunodeficiency (SCID) is characterized by defective ____ cell development which causes ____ cell dysfunction
T
| B
281
severe combined immunodeficiency mode of inheritence
x linked recessive and autosomal recessive
282
what is the treatment for severe combined immunodeficiency
stem cell transplant
283
the candidal antigen skin test used to determine the presence of cellular immunity via delayed type hypersensitivity reaction involves what cell types
macrophages (present ag)
CD4 t cells
CD8 t cells
284
CD4 and CD8 cells both secrete _____ which stimulates phagocytosis of candida by macrophages
interferon gamma
285
failure to generate a response to the candida skin test for example is reffered to as
anergy
286
describe the morphology in a hyperacute transplant rejection
gross mottling and cyanosis
| arterial fibrinoid necrosis and capillary thrombotic occlusion
287
defective signaling between CD4 T cells and B cells is consistent with what diagnosis which presents as recurrent infections and failure to thrive
hyperimmunoglobulin M syndrome
288
class switching occurs by splicing out DNA coding for different types of the _____ region
heavy chain constant region
289
class switching occurs when an activated CD4 t cells' ______ binds _____ on B cell
CD40L
| CD40
290
adenosine deaminase converts adenosine into _______
inosine
291
if adenosine deaminase in inhibited, metabolism of deoxyadenosine through an alternate pathway is phosphorylated into deoxyadenosine triphosphate which is a _______
toxic metabolite
292
build up of deoxyadenosine triphosphate activates the caspase system and inhibits _____________ which depletes cells of DNA precursors
ribonucleotide reductase
293
what cells are highly mitotically active and thus highly sensitive to inhibition of adenosine deaminase
lymphocytes
294
ADA inhibitors are best for treating ______ cancers
lymphocyte derived (hairy cell leukemia)
295
gene mutations in ADA lead to the autosomal recessive disease _________
sever combined immunodeficiency
296
numerous cytokines are released in sepsis, resulting in widespread systemic inflammation. one of the most important mediators of sepsis is _____
tumor necrosis factor
297
cytokines responsible for inducing systemic inflamatory response in spesis inclue TNF alpha, _______, and _______
iL-1
| IL-6
298
foreign bodies can elicit a ________ response, seen clinically as a tender, eythematous, borwn or purple papule, nodule or plaque
granulomatous
299
what form of immunoglobins form the immune complexes that deposit in the glomerular basement membrane in PSGN
IgG
300
what characteristic finding is seen on electron microscopy in PSGN
electron dense subepithelial humps
301
what type of hypersensitivity reaction is PSGN
type III
302
history of recurrent pneumonia infections, a diagnosis of celiac disease and anaphylactic reaction during transfusions is suggestive of what primary immunodeficiency
slelective IgA deficiency
303
why do patients with selective IgA deficiency have anyphylaxis during blood transfusions
their IgE antibodies with detect IgA from the transfused blood as foreign
304
________ selsction is the process by which only T cells expressing a TCR that is able to bind self MHC are allowed to survive
positive
305
during positive selection t cells interact with ________ cells expressing self MHC
thymic cortical epithelial cells
306
which happens first: positive or negative selection
positive
307
_____ selection is the proccess by which T cells possessing TCRs that bind with high affinity to self antigen or self MHCclass I or II are eliminated by apoptosis
negative
308
during negative selection, T cells interact with ______ cells
thymic medullary epithelial and dendritic cells
309
after ____ ocurs, subsequent pregnancies with Rh-positive fetuses with be at risk for hemolytic disease of the newborn
Rh alloimmunization (formation of B lymphocytes in the mother due to previous exposure)
310
what can be administered to pregnant mothers to avoid Rh alloimunizaiton
anti- Rh(D) immunoglobulin: a poluclonal antibody consisting of IgG ant-D antibodies
311
Sirolimus prevents T cell growth and proliferation by inhibiting _______ that leads to interuption in IL-2 signal trnasduction
mTOR (by binding FKbinding protein)
312
calcineurin inhibitors (tacrolimus, cyclosporine) are commonly used immunisoppression medications that function by blocking the translocation of NFAT resulting in reduced transcription of ______
IL-2
313
what do normal numbers of CD3 cells in flow cytrometry indicate
normal levels of circulating T cells
314
what do normal levels of CD19 cells in flow cytrometry indicate
normale levels of circulating B cells
315
HLA- ____, HLA-____, and HLA-____ genes encode MHC class II molecules on APC
DP
DQ
DR
316
HLA-___, HLA-____ and HLA-_____ genes encode MHC class I mo
A
B
C
317
recurring skin and mucosal infections with absence of purulences suggest what immune feficiency disease
leukocyte adhesion deficiency (LAD)
318
leukocyte adhesion deficiency is characterized by absence of ______
CD18
319
CD18 is necessary for the formation of _____ which are essetial for leukocyte adhesion to endothelial surfaces and migration to peripheral tissues in response to infection or inflammation
integrins
320
what is a single-celled buddy yeast with pseufohyphae and forms "germ tube" hyphal structures when grown in nutritionally rich serum
candidemia
321
how is superficial candida infection prevented by the the imune system
T lymphocytes (in particular helper T cells)
322
how is hematogenous spread of candida prevented by the immune system
neutrophils
323
which joint is spared in RA?
DIP
324
In RA, B CD4 T cells induce B cells to synthesize rheumatoid factor and _____
anti-citrullinated protein antibodies
325
rheumatoid factor is an antibody (usually IgM) specific for _______
Fc component of IgG
326
why do mothers with blood types A or B rarely have children with hemolytic disease of fetus and newborn
maternal antibodies (anti A or anti B) are of IgM type and cannot cross placenta
327
mothers with blood type O produce _____ antibodies (anti-A and anti B) which cause fetal hemolysis more commonly than in mothers who have type A or B blood
IgG
328
poison ivy dermatitis is what type of hypersensitivity reaction
type IV (delayed)
329
On flow cytrometric analysis of a sample of fetal thymus, a certain population of cells is identified that is positive for both CD4 and CD8 cell surface antiges. These cells are best characterized as ______
Immature cortical T lymphocytes
330
Pro-t cells arrive at the thymus as ______ cells: cells that lack both CD4 and CD8 antigens
Double negative
331
After TCR gene rearrangement of the beta chain genes, production of both the CD4 and CD8 antigens are simultaneously expressed , and these cells are referred to as _________ or immature T lymphocytes
Double positive T cells
332
Positive selection of T cells occurs in the of thymus
Cortex
333
Negative selection of T cells occurs in the _____ of thymus
Medulla
334
Which chain on the TCR undergoes rearrangement after CD4 and CD8 cell markers are expressed
Alpha chain
335
How is does IL-10 produce anti inflammatory effects
Reduces il-2 and IFN-gamma release from TH1 cells
Decreased MHC class II expression
Inhibits activated dendritic cells and macrophages
336
Macrophages infected with TB present mycobacterial antigens to CD4 cells and secrete IL-12 to induce activated which type of helper cells
TH1
337
Th1 cells secrete ____ to activate macrophages
IFN gamma
338
Neutrophil counts increase following administration of corticosteroid due to ________
Demargination (nutrophils previously attached to the vessel wall)
339
Which white blood cell count is acutely increased following administration of high dose prednisone shot
Neutrophils
340
Inactivated influenza vaccination stimulate formation of neutralizing antibodies against the ______ antigen of included strains
Hemagglutinin
341
In the influenza virus, Hemagglutinin attaches to sialic acid receptors on host respiratory cells inorder to _____
Viral entry into cells
342
Inactivated (killed or component) viral vaccines primarily generate a humoral immune respnose against extracellular viral antigens, preventing _____
Viral entry into the cell
343
Live attenuated viral vaccines can generate strong cell mediated immune response that _________ in addition to providing humoral immunity
Can kill virally infected cells
344
Ankylosing spondylitis is associated with a specific _______ serotype
Human leukocyte antigen cass II
345
What allele has a higher incidence in seronegative spondyloarthropathies than the general population
HLA B27
346
_________ results form destruction of fetal red blood cells by maternal antibodies directed against fetal erythrocyte antigens
Hemolytic disease of the newborn (erythroblastosis fetalis
347
What antibodies are involved in erythroblastosis fetalis
Maternal anti-Rh(D) IgG antibodies
348
Indication of a positive Coombs test
Autoimmune hemolysis
349
In chronic renal allograft rejection, Chronic cell mediated and antibody mediated response against donor antigens leads to obliteratie vascular wall thickening, tubular atrophy, and __________
Interstitial fibrosis
350
Macrophages produce ______ as a chemokine to induce chemotaxis and phagocytosis in neutrophils
IL-8
351
Pus consists of a thin, protein rich fluid, known as liquor puris, and dead leukocytes. primarily which leukocyte?
Neutrophils
352
In normal T cells, TCR activation --> _____ activation --> NFAT activation --> IL-2 gene trancription
Calcineurin
353
Calcineurin activates NFAT which stimulates ____ production which promotes gorwth and differentiation of T cells
IL-2
354
Cyclosporine and tacrolimus are used as immunosuppressants in transplant patients to inhibit _____ activation
Calcineurin
355
Patient with deficiencies in _______ often experience recurrent infections by Neisseria species
Complement factors that form the membrane attack complex (MAC)
356
```
A 3 month old girl is brought to the ED for fever, irritability, and vomitting for past 2 days. On exam she is ill-looking, lethargic, and febriel. Blood cultures grow TB. One of her brother died from disseminated mycobacterial infection during infancy. Impairment of which of the following protective mechanisms is most likely contributing to this patients infection:
Antibody production
Complement production
Interferon signaling
Isotype switching
Leukocyte adhesion
```
Interferon signaling
357
If a patient's neutrophils fail to turn blue on nitroblue tetazolium testing, what disease do they have
Chronic granulomatous disease
358
Mode of inheritance chronic granulomatous disease
X-linked
359
Inactivain mutations affecting what are present in chronic graulomatous disease
NADPH oxidase
360
NADPH oxidase is present in activated phagocytes and is responsible for producing ______ and activating __________
Reactive oxygen species
| Granule proteases
361
Patients with chronic granulmatous disease are at risk for recurrent infections with _____ positive organisms because they can destroy the hydrogen peroxide produced by their own metabolic activity
Catalase
362
When cellular proteins (or pathogen derived proteins) are degraded by proteasomes, some of the resulting peptide fragments are transported into the endoplasmic reticulum by _____ proteins adn loaded onto ______ molecules
```
TAP (transporter associated with antigen processing)
MHC class I
```
363
Acute cardiac transplant rejection shows endomyocardial biopsy with dense _____ infiltrate and cardiac myocyte damage
Mononuclear lymphocytic infiltrate
364
____ encodes a transcriptional regulator that converts activated CD4 cells into regulatory T cells, a population of T lymphocytes that inhibit immune activation
FOXP3
365
FOXP3 encodes a transcriptional regulator that coverts activated CD4 cells into ______
Regulatory T cells
366
Expression of FOXP3 drives the production of ____ which inhibits macrophage function, blocks inflammatory cytokine releases by CD4 cells, and downregulates expression of MHC cls II on APCs
IL 10
367
FOXP3 expression drives the production of ____ which inhibits B lymphocyte proliferation/activation and promotes Treg differentiation
TGF beta
368
FOXP3 expression drievs the production of ___ which binds with high affinity to CD80/86 on APCs making it less availible to activate T cells
CTLA-4
369
IPEX (immune dysregulation, polyendocrinopathy, enteropathy, and X linked transmission) is a genetic disorder that is due to a mutation in _____
FOXP3
370
Fluticasone drug class
Glucocorticd
371
How are intranasal glucocorticoids (fluticasone) helpful in treating allergic rhinitis
Inhibit transcription of genes that encode for inflammatry mediators --> suppress function of all leukocyte cell lines
372
Glucocorticoids decrease tissue production of proinflammatory prostaglandins and leukotrienes through the inhibition of ____
Phospholipase A2
373
Glucocorticoids decrease synthesis of almost all proinflammatory cytokines and increase what anti inflammatory cytokine
IL 10
374
What effect do glucocorticoids have on eosinophils, T cells,and monocytes, perhaps by decreasing Bcl-2 expression
Increase apoptosis
375
Most immunotherapy regimens use a fragment of the immunoglobuline with 1 valence (binding) site rather than the full immunoglobulin with 2 valence sites, because fragments are significantly smaller than the full immunoglobin, what function of the drug is improved
Improved tissue/tumor penetration and medication pharmakinetics
376
Antigen binding fragments (Fab) contain a variable domain and the first constant region of a heavy and light chain. Beause they do not contain a ___ region, they do not activate complement or trigger phafgocytosis
Fc
377
Why are Fab fragments no generally used in applications that require cell death such as cancer immunotherapy
Fab fragments lack Fc portion and do not activate coplement or trigger phagocytosis
378
List the required components of classical pathway of complement
C1 complex (C1q,r,s)
Fc portion of an IgM or IgG antibody that is bound to an antigen
C4
C2
379
List the required components of the lectin pathway of the complement cascade
Host pattern recofnition receptors bind carbohydrates produced only by foreign pathogens
Binding produces proteases
C4
C2
380
List the requirements of the alternative pathway of the complement cascade
Autoactivated C3b
Factor B
Factor D
381
Classical complement pathway activation with show high, low, or normal levels of the following: C4, C3, factor B
C4: low
C3: low
Factor B: normal
382
What are autlogous donor cells?
Cells obtained from the patient
383
What are allogenenic donor cells
Cells obtained from a related or an unrelated donor
384
A patient who has a history of ebstein barr virus that undergoes hematologic stem cell transplantation is at risk for what?
EBV reactivation
385
A patient who develops erythema and pruritus on the scalp, face and neck 2 days after reexposer to hair dye is likely experiencing what type of reaction
Allergic contact dermatitis (type iv, delayed-type, hypersensitivity reaction)
386
In the sensitization phase of allergic contact dermatitis (type IV sensitivity), cutaneous ____ cells take up haptens and present hapten-peptide complexes to CD4 and CD8 cells in lymph nodes
Langerhans cells
387
In the 2nd phase of contact dermititis, eicitation, what are the main effector cells
CD8
388
2 concerns following a vaccination are vasovagal syncope and anaphylaxis. How can they be differentiated?
Vasovagal: palor, absent respiratory symptoms, bradycardia
Anaphylaxis: urticaria/flushing, upper airway edema/bronchospasm, tachycardia
